X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/0a812366d68919613124e903cec376101f77c57b..2d0ffc9aa8662ec6d931bcb0d755ceb36fc62020:/lisp/apropos.el

diff --git a/lisp/apropos.el b/lisp/apropos.el
index e220b92892..19a8aab206 100644
--- a/lisp/apropos.el
+++ b/lisp/apropos.el
@@ -3,7 +3,7 @@
 ;; Copyright (C) 1989, 1994, 1995 Free Software Foundation, Inc.
 
 ;; Author: Joe Wells <jbw@bigbird.bu.edu>
-;; Rewritten: Daniel.Pfeiffer@Informatik.START.dbp.de, fax (+49 69) 7588-2389
+;; Rewritten: Daniel Pfeiffer <occitan@esperanto.org>
 ;; Keywords: help
 
 ;; This file is part of GNU Emacs.
@@ -19,8 +19,9 @@
 ;; GNU General Public License for more details.
 
 ;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs; see the file COPYING.  If not, write to
-;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+;; along with GNU Emacs; see the file COPYING.  If not, write to the
+;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+;; Boston, MA 02111-1307, USA.
 
 ;;; Commentary:
 
@@ -56,50 +57,67 @@
 
 ;;; Code:
 
+(defgroup apropos nil
+  "Apropos commands for users and programmers"
+  :group 'help
+  :prefix "apropos")
+
 ;; I see a degradation of maybe 10-20% only.
-(defvar apropos-do-all nil
+(defcustom apropos-do-all nil
   "*Whether the apropos commands should do more.
-Slows them down more or less.  Set this non-nil if you have a fast machine.")
+
+Slows them down more or less.  Set this non-nil if you have a fast machine."
+  :group 'apropos
+  :type 'boolean)
 
 
-(defvar apropos-symbol-face (if window-system 'bold)
-  "*Face for symbol name in apropos output or `nil'.  
-This looks good, but slows down the commands several times.")
+(defcustom apropos-symbol-face 'bold
+  "*Face for symbol name in Apropos output, or nil for none."
+  :group 'apropos
+  :type 'face)
 
-(defvar apropos-keybinding-face (if window-system 'underline)
-  "*Face for keybinding display in apropos output or `nil'.  
-This looks good, but slows down the commands several times.")
+(defcustom apropos-keybinding-face 'underline
+  "*Face for lists of keybinding in Apropos output, or nil for none."
+  :group 'apropos
+  :type 'face)
 
-(defvar apropos-label-face (if window-system 'italic)
-  "*Face for label (Command, Variable ...) in apropos output or `nil'.
-If this is `nil' no mouse highlighting occurs.
-This looks good, but slows down the commands several times.
-When this is a face name, as it is initially, it gets transformed to a
-text-property list for efficiency.")
+(defcustom apropos-label-face 'italic
+  "*Face for label (`Command', `Variable' ...) in Apropos output.
+A value of nil means don't use any special font for them, and also
+turns off mouse highlighting."
+  :group 'apropos
+  :type 'face)
 
-(defvar apropos-property-face (if window-system 'bold-italic)
-  "*Face for property name in apropos output or `nil'.  
-This looks good, but slows down the commands several times.")
+(defcustom apropos-property-face 'bold-italic
+  "*Face for property name in apropos output, or nil for none."
+  :group 'apropos
+  :type 'face)
 
-(defvar apropos-match-face (if window-system 'highlight)
-  "*Face for matching part in apropos-documentation/value output or `nil'.  
-This looks good, but slows down the commands several times.")
+(defcustom apropos-match-face 'secondary-selection
+  "*Face for matching text in Apropos documentation/value, or nil for none.
+This applies when you look for matches in the documentation or variable value
+for the regexp; the part that matches gets displayed in this font."
+  :group 'apropos
+  :type 'face)
 
 
-(defvar apropos-local-map
+(defvar apropos-mode-map
   (let ((map (make-sparse-keymap)))
     (define-key map "\C-m" 'apropos-follow)
+    (define-key map " "    'scroll-up)
+    (define-key map "\177" 'scroll-down)
+    (define-key map "q"    'quit-window)
     (define-key map [mouse-2] 'apropos-mouse-follow)
     (define-key map [down-mouse-2] nil)
     map)
-  "Local map active when displaying apropos output.")
+  "Keymap used in Apropos mode.")
 
 
 (defvar apropos-regexp nil
   "Regexp used in current apropos run.")
 
 (defvar apropos-files-scanned ()
-  "List of elc files already scanned in current run of `apropos-documentaion'.")
+  "List of elc files already scanned in current run of `apropos-documentation'.")
 
 (defvar apropos-accumulator ()
   "Alist of symbols already found in current apropos run.")
@@ -107,50 +125,86 @@ This looks good, but slows down the commands several times.")
 (defvar apropos-item ()
   "Current item in or for apropos-accumulator.")
 
+(defun apropos-mode ()
+  "Major mode for following hyperlinks in output of apropos commands.
+
+\\{apropos-mode-map}"
+  (interactive)
+  (kill-all-local-variables)
+  (use-local-map apropos-mode-map)
+  (setq major-mode 'apropos-mode
+	mode-name "Apropos"))
+
+;;;###autoload
+(defun apropos-variable (regexp &optional do-all)
+  "Show user variables that match REGEXP.
+With optional prefix ARG or if `apropos-do-all' is non-nil, also show
+normal variables."
+  (interactive (list (read-string
+                      (concat "Apropos "
+                              (if (or current-prefix-arg apropos-do-all)
+				  "variable"
+				"user option")
+                              " (regexp): "))
+                     current-prefix-arg))
+  (apropos-command regexp nil
+		   (if (or do-all apropos-do-all)
+		       #'(lambda (symbol)
+			   (and (boundp symbol)
+				(get symbol 'variable-documentation)))
+		     'user-variable-p)))
+
 ;; For auld lang syne:
 ;;;###autoload
 (fset 'command-apropos 'apropos-command)
 ;;;###autoload
-(defun apropos-command (apropos-regexp &optional do-all)
-  "Shows commands (interactively callable functions) that match REGEXP.
-With optional prefix ARG or if `apropos-do-all' is non-nil, also show
-variables."
-  (interactive (list (read-string (concat "Apropos command "
-					  (if (or current-prefix-arg
-						  apropos-do-all)
-					      "or variable ")
-					  "(regexp): "))
+(defun apropos-command (apropos-regexp &optional do-all var-predicate)
+  "Show commands (interactively callable functions) that match REGEXP.
+With optional prefix ARG, or if `apropos-do-all' is non-nil, also show
+noninteractive functions.
+
+If VAR-PREDICATE is non-nil, show only variables, and only those that
+satisfy the predicate VAR-PREDICATE."
+  (interactive (list (read-string (concat
+				   "Apropos command "
+				   (if (or current-prefix-arg
+					   apropos-do-all)
+				       "or function ")
+				   "(regexp): "))
 		     current-prefix-arg))
   (let ((message
-	 (let ((standard-output (get-buffer-create "*Help*")))
+	 (let ((standard-output (get-buffer-create "*Apropos*")))
 	   (print-help-return-message 'identity))))
     (or do-all (setq do-all apropos-do-all))
     (setq apropos-accumulator
 	  (apropos-internal apropos-regexp
-			    (if do-all
-				(lambda (symbol) (or (commandp symbol)
-						     (user-variable-p symbol)))
-			      'commandp)))
-    (if (apropos-print
-	 t
-	 (lambda (p)
-	   (let (doc symbol)
-	     (while p
-	       (setcar p (list
-			  (setq symbol (car p))
-			  (if (commandp symbol)
-			      (if (setq doc (documentation symbol t))
-				  (substring doc 0 (string-match "\n" doc))
-				"(not documented)"))
-			  (and do-all
-			       (user-variable-p symbol)
-			       (if (setq doc (documentation-property
-					      symbol 'variable-documentation t))
-				   (substring doc 0
-					      (string-match "\n" doc))))))
-	       (setq p (cdr p)))))
-	 nil)
-	(and message (message message)))))
+			    (or var-predicate
+				(if do-all 'functionp 'commandp))))
+    (let ((tem apropos-accumulator))
+      (while tem
+	(if (get (car tem) 'apropos-inhibit)
+	    (setq apropos-accumulator (delq (car tem) apropos-accumulator)))
+	(setq tem (cdr tem))))
+    (let ((p apropos-accumulator)
+	  doc symbol)
+      (while p
+	(setcar p (list
+		   (setq symbol (car p))
+		   (unless var-predicate
+		     (if (functionp symbol)
+			 (if (setq doc (documentation symbol t))
+			     (substring doc 0 (string-match "\n" doc))
+			   "(not documented)")))
+		   (and var-predicate
+			(funcall var-predicate symbol)
+			(if (setq doc (documentation-property
+				       symbol 'variable-documentation t))
+			    (substring doc 0
+				       (string-match "\n" doc))))))
+	(setq p (cdr p))))
+    (and (apropos-print t nil)
+	 message
+	 (message message))))
 
 
 ;;;###autoload
@@ -167,29 +221,56 @@ Returns list of symbols and documentation found."
 			       (lambda (symbol)
 				 (or (fboundp symbol)
 				     (boundp symbol)
+				     (facep symbol)
 				     (symbol-plist symbol))))))
+  (let ((tem apropos-accumulator))
+    (while tem
+      (if (get (car tem) 'apropos-inhibit)
+	  (setq apropos-accumulator (delq (car tem) apropos-accumulator)))
+      (setq tem (cdr tem))))
+  (let ((p apropos-accumulator)
+	symbol doc properties)
+    (while p
+      (setcar p (list
+		 (setq symbol (car p))
+		 (when (fboundp symbol)
+		   (if (setq doc (condition-case nil
+				     (documentation symbol t)
+				   (void-function
+				    "(alias for undefined function)")))
+		       (substring doc 0 (string-match "\n" doc))
+		     "(not documented)"))
+		 (when (boundp symbol)
+		   (if (setq doc (documentation-property
+				  symbol 'variable-documentation t))
+		       (substring doc 0 (string-match "\n" doc))
+		     "(not documented)"))
+		 (when (setq properties (symbol-plist symbol))
+		   (setq doc (list (car properties)))
+		   (while (setq properties (cdr (cdr properties)))
+		     (setq doc (cons (car properties) doc)))
+		   (mapconcat #'symbol-name (nreverse doc) " "))
+		 (when (get symbol 'widget-type)
+		   (if (setq doc (documentation-property
+				  symbol 'widget-documentation t))
+		       (substring doc 0
+				  (string-match "\n" doc))
+		     "(not documented)"))
+		 (when (facep symbol)
+		   (if (setq doc (documentation-property
+				  symbol 'face-documentation t))
+		       (substring doc 0
+				  (string-match "\n" doc))
+		     "(not documented)"))
+		 (when (get symbol 'custom-group)
+		   (if (setq doc (documentation-property
+				  symbol 'group-documentation t))
+		       (substring doc 0
+				  (string-match "\n" doc))
+		     "(not documented)"))))
+      (setq p (cdr p))))
   (apropos-print
    (or do-all apropos-do-all)
-   (lambda (p)
-     (let (symbol doc)
-       (while p
-	 (setcar p (list
-		    (setq symbol (car p))
-		    (if (fboundp symbol)
-			(if (setq doc (documentation symbol t))
-			    (substring doc 0 (string-match "\n" doc))
-			  "(not documented)"))
-		    (if (boundp symbol)
-			(if (setq doc (documentation-property
-				       symbol 'variable-documentation t))
-			    (substring doc 0
-				       (string-match "\n" doc))
-			  "(not documented)"))
-		    (if (setq doc (symbol-plist symbol))
-			(if (eq (setq doc (/ (length doc) 2)) 1)
-			    "1 property"
-			  (concat doc " properties")))))
-	 (setq p (cdr p)))))
    nil))
 
 
@@ -215,12 +296,12 @@ Returns list of symbols and values found."
 	(if (or f v p)
 	    (setq apropos-accumulator (cons (list symbol f v p)
 					    apropos-accumulator))))))
-  (apropos-print nil nil t))
+  (apropos-print nil t))
 
 
 ;;;###autoload
 (defun apropos-documentation (apropos-regexp &optional do-all)
-  "Show symbols whose names or documentation contain matches for REGEXP.
+  "Show symbols whose documentation contain matches for REGEXP.
 With optional prefix ARG or if `apropos-do-all' is non-nil, also use
 documentation that is not stored in the documentation file and show key
 bindings.
@@ -238,11 +319,10 @@ Returns list of symbols and documentation found."
 	      (mapatoms
 	       (lambda (symbol)
 		 (setq f (apropos-safe-documentation symbol)
-		       v (get symbol 'variable-documentation)
-		       v (if (integerp v) nil v))
-		 (or (string-match apropos-regexp (symbol-name symbol))
-		     (setq f (apropos-documentation-internal f)
-			   v (apropos-documentation-internal v)))
+		       v (get symbol 'variable-documentation))
+		 (if (integerp v) (setq v))
+		 (setq f (apropos-documentation-internal f)
+		       v (apropos-documentation-internal v))
 		 (if (or f v)
 		     (if (setq apropos-item
 			       (cdr (assq symbol apropos-accumulator)))
@@ -254,7 +334,7 @@ Returns list of symbols and documentation found."
 		       (setq apropos-accumulator
 			     (cons (list symbol f v)
 				   apropos-accumulator)))))))
-	  (apropos-print do-all nil t))
+	  (apropos-print nil t))
       (kill-buffer standard-input))))
 
 
@@ -307,57 +387,64 @@ Returns list of symbols and documentation found."
 ;; Finds all documentation related to APROPOS-REGEXP in internal-doc-file-name.
 
 (defun apropos-documentation-check-doc-file ()
-  (let (type symbol beg end)
+  (let (type symbol (sepa 2) sepb beg end)
+    (insert ?\^_)
+    (backward-char)
     (insert-file-contents (concat doc-directory internal-doc-file-name))
-    (while (re-search-forward apropos-regexp nil t)
-      (setq beg (match-beginning 0)
-	    end (point))
-      (search-backward "\C-_")
-      (if (> (point) beg)
-	  ()
-	(or (setq type (if (eq ?F (char-after (1+ (point))))
-			   1		;function documentation
-			 2)		;variable documentation
-		  symbol (prog2
-			     (forward-char 2)
-			     (read))
-		  beg (- beg (point) 1)
-		  end (- end (point) 1)
-		  doc (buffer-substring
-		       (1+ (point))
-		       (if (search-forward "\C-_" nil 'move)
-			   (1- (point))
-			 (point)))
-		  apropos-item (assq symbol apropos-accumulator))
-	    (setq apropos-item (list symbol nil nil)
-		  apropos-accumulator (cons apropos-item apropos-accumulator)))
-	(and apropos-match-face
-	     (>= beg 0)
-	     (put-text-property beg end 'face apropos-match-face doc))
-	(setcar (nthcdr type apropos-item) doc)))))
+    (forward-char)
+    (while (save-excursion
+	     (setq sepb (search-forward "\^_"))
+	     (not (eobp)))
+      (beginning-of-line 2)
+      (if (save-restriction
+	    (narrow-to-region (point) (1- sepb))
+	    (re-search-forward apropos-regexp nil t))
+	  (progn
+	    (setq beg (match-beginning 0)
+		  end (point))
+	    (goto-char (1+ sepa))
+	    (or (setq type (if (eq ?F (preceding-char))
+			       1	; function documentation
+			     2)		; variable documentation
+		      symbol (read)
+		      beg (- beg (point) 1)
+		      end (- end (point) 1)
+		      doc (buffer-substring (1+ (point)) (1- sepb))
+		      apropos-item (assq symbol apropos-accumulator))
+		(setq apropos-item (list symbol nil nil)
+		      apropos-accumulator (cons apropos-item
+						apropos-accumulator)))
+	    (if apropos-match-face
+		(put-text-property beg end 'face apropos-match-face doc))
+	    (setcar (nthcdr type apropos-item) doc)))
+      (setq sepa (goto-char sepb)))))
 
 (defun apropos-documentation-check-elc-file (file)
   (if (member file apropos-files-scanned)
       nil
-    (let (symbol doc beg end end1 this-is-a-variable)
+    (let (symbol doc beg end this-is-a-variable)
       (setq apropos-files-scanned (cons file apropos-files-scanned))
       (erase-buffer)
       (insert-file-contents file)
       (while (search-forward "\n#@" nil t)
 	;; Read the comment length, and advance over it.
 	(setq end (read)
-	      beg (point)
-	      end (+ (point) end 1))
-	(if (re-search-forward apropos-regexp end t)
+	      beg (1+ (point))
+	      end (+ (point) end -1))
+	(forward-char)
+	(if (save-restriction
+	      ;; match ^ and $ relative to doc string
+	      (narrow-to-region beg end)
+	      (re-search-forward apropos-regexp nil t))
 	    (progn
-	      (goto-char end)
-	      (setq doc (buffer-substring (1+ beg) (- end 2))
-		    end1 (- (match-end 0) beg 1)
-		    beg (- (match-beginning 0) beg 1)
-		    this-is-a-variable (looking-at "(defvar\\|(defconst")
+	      (goto-char (+ end 2))
+	      (setq doc (buffer-substring beg end)
+		    end (- (match-end 0) beg)
+		    beg (- (match-beginning 0) beg)
+		    this-is-a-variable (looking-at "(def\\(var\\|const\\) ")
 		    symbol (progn
 			     (skip-chars-forward "(a-z")
-			     (forward-char 1)
+			     (forward-char)
 			     (read))
 		    symbol (if (consp symbol)
 			       (nth 1 symbol)
@@ -371,12 +458,11 @@ Returns list of symbols and documentation found."
 			      apropos-accumulator (cons apropos-item
 							apropos-accumulator)))
 		    (if apropos-match-face
-			(put-text-property beg end1 'face apropos-match-face
+			(put-text-property beg end 'face apropos-match-face
 					   doc))
 		    (setcar (nthcdr (if this-is-a-variable 2 1)
 				    apropos-item)
-			    doc)))))
-	(goto-char end)))))
+			    doc)))))))))
 
 
 
@@ -404,81 +490,118 @@ Will return nil instead."
 
 
 
-(defun apropos-print (do-keys doc-fn spacing)
-  "Output result of various apropos commands with `apropos-regexp'.
-APROPOS-ACCUMULATOR is a list.  Optional DOC-FN is called for each element
-of apropos-accumulator and may modify it resulting in (symbol fn-doc
-var-doc [plist-doc]).  Returns sorted list of symbols and documentation
-found."
+(defvar apropos-label-properties nil
+  "List of face properties to use for a label.
+Bound by `apropos-print' for use by `apropos-print-doc'.")
+
+(defun apropos-print (do-keys spacing)
+  "Output result of apropos searching into buffer `*Apropos*'.
+The value of `apropos-accumulator' is the list of items to output.
+Each element should have the format (SYMBOL FN-DOC VAR-DOC [PLIST-DOC]).
+The return value is the list that was in `apropos-accumulator', sorted
+alphabetically by symbol name; but this function also sets
+`apropos-accumulator' to nil before returning."
   (if (null apropos-accumulator)
       (message "No apropos matches for `%s'" apropos-regexp)
-    (if doc-fn
-	(funcall doc-fn apropos-accumulator))
     (setq apropos-accumulator
 	  (sort apropos-accumulator (lambda (a b)
-				 (string-lessp (car a) (car b)))))
-    (and apropos-label-face
-	 (symbolp apropos-label-face)
-	 (setq apropos-label-face `(face ,apropos-label-face
-					 mouse-face highlight)))
+				      (string-lessp (car a) (car b)))))
+    (setq apropos-label-properties
+	  (if (and apropos-label-face
+		   (symbolp apropos-label-face))
+	      `(face ,apropos-label-face
+		     mouse-face highlight)))
     (with-output-to-temp-buffer "*Apropos*"
       (let ((p apropos-accumulator)
 	    (old-buffer (current-buffer))
 	    symbol item point1 point2)
-	(save-excursion
-	  (set-buffer standard-output)
-	  (if window-system
-	      (insert (substitute-command-keys
-		       "Click \\<apropos-local-map>\\[apropos-mouse-follow] to get full documentation.\n")))
-	  (insert (substitute-command-keys
-		   "In this buffer, type \\<apropos-local-map>\\[apropos-follow] to get full documentation.\n\n"))
-	  (use-local-map apropos-local-map)
-	  (while (consp p)
-	    (or (not spacing) (bobp) (terpri))
-	    (setq apropos-item (car p)
-		  symbol (car apropos-item)
-		  p (cdr p)
-		  point1 (point))
-	    (princ symbol)		        ;print symbol name
-	    (setq point2 (point))
-	    ;; don't calculate key-bindings unless needed
-	    (and do-keys
-		 (commandp symbol)
-		 (indent-to 30 1)
-		 (insert
-		  (if (setq item (save-excursion
-				   (set-buffer old-buffer)
-				   (where-is-internal symbol)))
-		      (mapconcat
+	(set-buffer standard-output)
+	(apropos-mode)
+	(if window-system
+	    (insert "If you move the mouse over text that changes color,\n"
+		    (substitute-command-keys
+		     "you can click \\[apropos-mouse-follow] to get more information.\n")))
+	(insert (substitute-command-keys
+		 "In this buffer, type \\[apropos-follow] to get full documentation.\n\n"))
+	(while (consp p)
+	  (or (not spacing) (bobp) (terpri))
+	  (setq apropos-item (car p)
+		symbol (car apropos-item)
+		p (cdr p)
+		point1 (point))
+	  (princ symbol)		        ; print symbol name
+	  (setq point2 (point))
+	  ;; Calculate key-bindings if we want them.
+	  (and do-keys
+	       (commandp symbol)
+	       (indent-to 30 1)
+	       (if (let ((keys
+			  (save-excursion
+			    (set-buffer old-buffer)
+			    (where-is-internal symbol)))
+			 filtered)
+		     ;; Copy over the list of key sequences,
+		     ;; omitting any that contain a buffer or a frame.
+		     (while keys
+		       (let ((key (car keys))
+			     (i 0)
+			     loser)
+			 (while (< i (length key))
+			   (if (or (framep (aref key i))
+				   (bufferp (aref key i)))
+			       (setq loser t))
+			   (setq i (1+ i)))
+			 (or loser
+			     (setq filtered (cons key filtered))))
+		       (setq keys (cdr keys)))
+		     (setq item filtered))
+		   ;; Convert the remaining keys to a string and insert.
+		   (insert
+		    (mapconcat
+		     (lambda (key)
+		       (setq key (condition-case () 
+				     (key-description key)
+				   (error)))
 		       (if apropos-keybinding-face
-			   (lambda (key)
-			     (setq key (key-description key))
-			     (put-text-property 0 (length key)
-						'face apropos-keybinding-face
-						key)
-			     key)
-			 'key-description)
-		       item ", ")
-		    "(not bound to any keys)")))
-	    (terpri)
-	    ;; only now so we don't propagate text attributes all over
-	    (put-text-property point1 point2 'item
-			       (if (eval `(or ,@(cdr apropos-item)))
-				   (car apropos-item)
-				 apropos-item))
-	    (if apropos-symbol-face
-		(put-text-property point1 point2 'face apropos-symbol-face))
-	    (apropos-print-doc 'describe-function 1
-			       (if (commandp symbol)
-				   "Command"
-				 (if (apropos-macrop symbol)
-				     "Macro"
-				   "Function"))
-			       do-keys)
-	    (apropos-print-doc 'describe-variable 2
-			       "Variable" do-keys)
-	    (apropos-print-doc 'apropos-describe-plist 3
-			       "Plist" nil))))))
+			   (put-text-property 0 (length key)
+					      'face apropos-keybinding-face
+					      key))
+		       key)
+		     item ", "))
+		 (insert "M-x")
+		 (put-text-property (- (point) 3) (point)
+				    'face apropos-keybinding-face)
+		 (insert " " (symbol-name symbol) " ")
+		 (insert "RET")
+		 (put-text-property (- (point) 3) (point)
+				    'face apropos-keybinding-face)))
+	  (terpri)
+	  ;; only now so we don't propagate text attributes all over
+	  (put-text-property point1 point2 'item
+			     (if (eval `(or ,@(cdr apropos-item)))
+				 (car apropos-item)
+			       apropos-item))
+	  (if apropos-symbol-face
+	      (put-text-property point1 point2 'face apropos-symbol-face))
+	  (apropos-print-doc 'describe-function 1
+			     (if (commandp symbol)
+				 "Command"
+			       (if (apropos-macrop symbol)
+				   "Macro"
+				 "Function"))
+			     t)
+	  ;; We used to use customize-variable-other-window instead
+	  ;; for a customizable variable, but that is slow.
+	  ;; It is better to show an ordinary help buffer
+	  ;; and let the user click on the customization button
+	  ;; in that buffer, if he wants to.
+	  (apropos-print-doc 'describe-variable 2 "Variable" t)
+	  (apropos-print-doc 'customize-group-other-window 6 "Group" t)
+	  (apropos-print-doc 'customize-face-other-window 5 "Face" t)
+	  (apropos-print-doc 'widget-browse-other-window 4 "Widget" t)
+	  (apropos-print-doc 'apropos-describe-plist 3
+			     "Plist" nil))
+	(setq buffer-read-only t))))
   (prog1 apropos-accumulator
     (setq apropos-accumulator ())))	; permit gc
 
@@ -501,46 +624,47 @@ found."
 	(put-text-property (- (point) 2) (1- (point))
 			   'action action)
 	(insert str ": ")
-	(if apropos-label-face
+	(if apropos-label-properties
 	    (add-text-properties (- (point) (length str) 2)
 				 (1- (point))
-				 apropos-label-face))
+				 apropos-label-properties))
 	(insert (if do-keys (substitute-command-keys i) i))
 	(or (bolp) (terpri)))))
 
 
 (defun apropos-mouse-follow (event)
   (interactive "e")
-  (let ((other (if (eq (current-buffer) (get-buffer "*Help*"))
+  (let ((other (if (eq (current-buffer) (get-buffer "*Apropos*"))
 		   ()
 		 (current-buffer))))
-    (set-buffer (window-buffer (posn-window (event-start event))))
-    (goto-char (posn-point (event-start event)))
-    ;; somehow when clicking with the point in another window, undoes badly
-    (undo-boundary)
-    (apropos-follow other)))
+    (save-excursion
+      (set-buffer (window-buffer (posn-window (event-start event))))
+      (goto-char (posn-point (event-start event)))
+      (or (and (not (eobp)) (get-text-property (point) 'mouse-face))
+	  (and (not (bobp)) (get-text-property (1- (point)) 'mouse-face))
+	  (error "There is nothing to follow here"))
+      (apropos-follow other))))
 
 
 (defun apropos-follow (&optional other)
   (interactive)
-  (let ((point (point))
-	(item
-	 (or (and (not (eobp)) (get-text-property (point) 'item))
-	     (and (not (bobp)) (get-text-property (1- (point)) 'item))))
-	action action-point)
-    (if (null item)
+  (let* (;; Properties are always found at the beginning of the line.
+	 (bol (save-excursion (beginning-of-line) (point)))
+	 ;; If there is no `item' property here, look behind us.
+	 (item (get-text-property bol 'item))
+	 (item-at (if item nil (previous-single-property-change bol 'item)))
+	 ;; Likewise, if there is no `action' property here, look in front.
+	 (action (get-text-property bol 'action))
+	 (action-at (if action nil (next-single-property-change bol 'action))))
+    (and (null item) item-at
+	 (setq item (get-text-property (1- item-at) 'item)))
+    (and (null action) action-at
+	 (setq action (get-text-property action-at 'action)))
+    (if (not (and item action))
 	(error "There is nothing to follow here"))
-    (if (consp item)
-	(error "There is nothing to follow in `%s'" (car item)))
-    (while (if (setq action-point
-		     (next-single-property-change (point) 'action))
-	       (<= action-point point))
-      (goto-char (1+ action-point))
-      (setq action action-point))
-    (funcall
-     (prog1 (get-text-property (or action action-point (point)) 'action)
-       (if other (set-buffer other)))
-     item)))
+    (if (consp item) (error "There is nothing to follow in `%s'" (car item)))
+    (if other (set-buffer other))
+    (funcall action item)))
 
 
 
@@ -554,6 +678,9 @@ found."
     (if apropos-symbol-face
 	(put-text-property 8 (- (point) 14) 'face apropos-symbol-face))
     (insert (apropos-format-plist symbol "\n  "))
-    (princ ")")))
+    (princ ")")
+    (print-help-return-message)))
+
+(provide 'apropos)
 
 ;;; apropos.el ends here